US Secretary of State Rex Tillerson, who was in Guam on a previously scheduled visit, said he did not believe there was an imminent threat from North Korea

North Korea on Thursday said it was planning to fire missiles over Japan to land in the ocean near Guam in what may be a shift in its weapons testing program, not a threat of an immediate attack on Guam and its US military bases.

Pyongyang and US President Donald Trump got into a war of words this week that unnerved regional powers and global investors. Trump said the North “will be met with fire and fury like the world has never seen” if it threatened the United States.

The timing of Trump’s comment and the implicit threat of use of nuclear weapons was not lost, coming as it did in the same week that Japan commemorated the 72nd anniversary of the atomic bombings of Hiroshima and Nagasaki.

Pyongyang responded Wednesday with what was perceived as a plan for a missile strike on Guam. Less than 24-hours later, North Korea said it planned to fire four intermediate-range missiles over Japan to land 30-40 km (18-25 miles) from Guam, more than 3,000 km (2,000 miles) to the south.

Masao Okonogi, professor emeritus at Japan’s Keio University, said the latest North Korean report suggested Pyongyang was issuing a warning or advance notice of changes to its missile testing program rather than threatening an attack.

“I believe this is a message saying they plan to move missile tests from the Sea of Japan to areas around Guam,” he told Reuters. “By making this advance notice, they are also sending a tacit message that what they are going to do is not an actual attack.”

Guam is home to about 163,000 people and US military installations that include a submarine squadron and the Anderson air force base.

North Korea’s state news service KCNA reported the country will complete its testing plans in mid-August, and await leader Kim Jong Un’s order. The report cited General Kim Rak Gyom, commander of the Strategic Force of the Korean People’s Army.

Power boasts

The United States and South Korea remain technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.

US Defence Secretary Jim Mattis issued a stark warning on Wednesday, telling Pyongyang the United States and its allies would win any arms race or conflict.

“The DPRK should cease any consideration of actions that would lead to the end of its regime and the destruction of its people,” Mattis said in a statement, using the acronym for North Korea’s official name, the Democratic People’s Republic of Korea.

Tensions have risen since North Korea carried out two nuclear bomb tests last year and two intercontinental ballistic missile tests in July. Trump has said he will not allow Pyongyang to develop a nuclear weapon capable of hitting the United States.

On Wednesday, Trump boasted about US nuclear capabilities.

“My first order as President was to renovate and modernize our nuclear arsenal. It is now far stronger and more powerful than ever before,” Trump said on Twitter. “Hopefully we will never have to use this power, but there will never be a time that we are not the most powerful nation in the world!”

US Secretary of State Rex Tillerson, who was in Guam on a previously scheduled visit, played down the rhetoric, saying he did not believe there was an imminent threat from North Korea and “Americans should sleep well at night.”

A tourist walks his dog along Tumon beach on the island of Guam, a U.S. Pacific Territory, August 10, 2017. Reuters/Erik De Castro

Earlier on Wednesday, Guam Governor Eddie Calvo dismissed the threat and said the island was prepared for “any eventuality” with strategically placed defences. He said he had been in touch with the White House and there was no change in the threat level.

Confrontation

While North Korea appeared to be responding to Trump’s “fire and fury” comments with the threat to Guam, it may also be Pyongyang’s angry reaction to the tougher economic sanctions imposed by the UN Security Council on Saturday.

The sanctions — approved by China, North Korea’s main ally, and Russia, which both have a border with North Korea — threaten to reduce North Korea’s export earnings by a third, or US$1 billion.

UN members approving the sanctions, including Russia and China, will “pay dearly,” North Korea warned in a statement on KCNA.

Pyongyang accuses Washington of preparing for an attack on North Korea under the guise of what the US calls a “preventive war” and has said any plans to execute this would be met with an all-out conflict.

“It is a daydream for the US to think that its mainland is an invulnerable Heavenly kingdom,” according to a KCNA statement.

Washington has warned it is ready to use force if needed to stop North Korea’s ballistic missile and nuclear programs but that it prefers global diplomatic action, including sanctions.

China has consistently urged both sides to work to lower tensions.

Influential Chinese state-run tabloid the Global Times said the North Korean nuclear issue was heading towards confrontation and it was time for the United States to respond to Pyongyang’s security concerns.

“North Korea has almost been completely isolated by the outside world. Under such extreme circumstances, Pyongyang will weigh all its possible options,” it said in an editorial on its website on Thursday. “Washington should stimulate Pyongyang’s desire to engage with the outside world and return to the international community.”

A senior U.S. official who deals with the Korean issue said the “fire and fury” comment, which was Trump’s strongest warning yet for North Korea, was “unplanned and spontaneous”.

“There had not been any discussions about escalating the rhetoric in response to Kim’s statements or about the possible effects of doing that,” the official said.

US Senator John McCain, a Republican and chairman of the Armed Services Committee, criticized Trump’s comment.

“I take exception to the President’s comments because you gotta be able to do what you say you’re gonna do,” the Arizona Senator told KTAR radio on Tuesday.

However, White House spokeswoman Sarah Sanders told reporters national security officials had been aware of the tone of Trump’s message before he gave it.

“The words were his own. The tone and strength of the message were discussed beforehand,” Sanders said.